Shock absorber



FIG. 1 is a front isometric view of the shock absorber together with environmental structure that forms no part of the claimed design;

FIG. 2 is a front isometric view thereof without the environmental structure;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is right side view thereof;

FIG. 6 is a left side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines in the drawings represent portions of the shock absorber that form no part of the claimed design. 

CLAIM The ornamental design for a shock absorber, as shown and described. 